Field of the Invention
This invention relates to a disc recording/reproducing apparatus and, more particularly, to a burn-in diagnostic technique for disc recording/reproducing apparatus.
In order to screen apparatus which are possibly suffering from time-and stress-related troubles, it is known to put, the apparatus through a test known as a burn-in, wherein the apparatus is subjected to a predetermined temperature during the production process.
In executing the burn-in for the disc recording/reproducing apparatus, the apparatus is placed in a burn-in chamber, which is a constant temperature tank, and is connected to a host computer by an interfacing cabling. A test, program is down-line loaded from the host computer to the disc recording/reproducing apparatus under control of the host computer, and is run under instructions issued from the host computer.
The results obtained through the execution of the test program are collected by the host computer for determining if the disc recording/reproducing apparatus is or is not in a normal operating state. This diagnostic system is referred to as the on-line checking system.
When implementing such an on-line checking system, it is known to connect a host computer to one disc recording/reproducing system (1 to 1 or 1:1 system) as shown in FIG. 1 or to connect a host computer to an N-number of the disc recording/reproducing apparatus (1 to N or 1:N system) as shown in FIG. 2. With the 1:N system, a burn-in arrangement of a smaller scale suffices. However, in this case, complicated interfacing cabling is necessary for interconnecting the host computer and the plurality of disc recording/reproducing apparatus. For example, with the use of a small computer system interface (SCSI) for interfacing between the host computer and the disc recording/reproducing apparatus, the interfacing cable takes the form of a 50-core cable, which can be handled only with extremely laborsome operations.
Also, among burn-in test items, there are, for example, detection of defective blocks, arranging the defective blocks in spare blocks, counting the number of errors and calculating the error rate. Accordingly, it takes approximately twenty hours to perform each burn-in operation. Hence the weight of burn-in the production process is tremendous not only from the aspect of the operating time but also from the aspect of the equipment including the equipment investment or equipment space. The overall of a plant depends to a large extent on how many disc recording/reproducing apparatus can be put through a burn-in at one time with the existing equipment.